I think there is more than a bit of inappropriate conflation here...
Or are you just the means to pass on your DNA?
"attracted to men whose genetic makeup differs from their own" which
"increases the chances for a healthy pregnancy and a healthy baby,"
Is not the same as having a happy long-term relationship. Arguing a "healthy" baby is essential to that relationship disses childless couples - and what about "unhealthy" babies
I have been happily unmarried to the same woman for 15 years. We're just fine by ourselves - much to the consternation of several traditionalist stick in the mud associates.
I also grew up in a viciously abusive home where two people had nothing in common except kids. It was pure hell throughout.
How does that figure into the hypothesis?
Attraction is the beginning of the relationship. If it wears off - with the T-shirt smell, I guess - before the couple spawn, then they go their own ways. If the pill keeps them from spawning before they figure out they have nothing in common except libido, great! Too many times they don't and then junior becomes the only reason to stick it out.
This is the bottom line: Traditionalists eschew - and more importantly want to persuade or compel you to eschew - pre-marital sex, birth control, and divorce. They prefer that people who hate each others guts - and take it out on their kids on a daily basis - stay married and perpetuate the misery...
Because misery loves and needs company.
The traditional model doesn't and never did work. It has produced at least as many miserable, damaged people as healthy ones, and I think a lot more. More liberal models may be no better but can't be worse. It takes years to outgrow the abuse these loveless homes heap on kids.
That at least should tip the debate. Do it for the kids...